2015.2: update release notes
2015.2: update release notes

lokik/sfepy,BubuLK/sfepy,BubuLK/sfepy,rc/sfepy,lokik/sfepy,vlukes/sfepy,RexFuzzle/sfepy,RexFuzzle/sfepy,vlukes/sfepy,lokik/sfepy,sfepy/sfepy,RexFuzzle/sfepy,rc/sfepy,vlukes/sfepy,RexFuzzle/sfepy,sfepy/sfepy,lokik/sfepy,sfepy/sfepy,BubuLK/sfepy,rc/sfepy